Vytorin and Zetia, Merck & Co.’s anti-cholesterol medications, are coming under fire again. A new study has found that a much older – and cheaper – drug reduced artery plaque much better in eight months than ezetimibe, the active ingredient in both Vytorin and Zetia.
According to USA Today, this latest study was released Sunday at an American Heart Association meeting and published online by the New England Journal of Medicine.
Vytorin, developed and marketed jointly by Merck and Schering-Plough, is a combination of cholesterol-lowering Zetia and the statin Zocor. Vytorin was approved by the Food & Drug Administration in 2004 to treat both sources of cholesterol – absorption in the intestine of both biliary and dietary cholesterol, and production in the liver and peripheral tissues. It was believed that the treatment of cholesterol from both sources would likely result in lower cholesterol levels. It was likewise theorized that this reduction in cholesterol would in turn reduce the amount of plaque buildup in the arteries, thus reducing the risk of heart attack and stroke.
According to USA Today, the latest Vytorin and Zetia study compared ezetimibe with prescription Niaspan, made by Abbott Laboratories. Niaspan is a slow-release form of niacin, a drug which has been around for 50 years. The Abbott-sponsored study involved 363 patients who had heart disease or a high risk of heart problems. All had been taking statins and had relatively low levels of bad cholesterol. Half of the patients were given Niaspan, and half were given Zetia, USA Today said.
The study found that Niaspan reduced plaque in neck arteries by 2%,while Zetia did not. Two people in the Niaspan group had heart attacks or other major cardiac events, compared with nine in the Zetia group.
While the study did have some limitations, – a small size, and the fact that it was stopped after 14 months because patients in the niacin group were doing better – it is not the first to question the supposed benefits of Vytorin and Zetia. The drugs have been the subject of controversy since the ENHANCE study was released in January 2008. ENHANCE found that the Vytorin was no better than a cheaper, generic statin in preventing clogged arteries, and raised serious questions about the effectiveness of both Vytorin and Zetia. What’s more, Merck and Schering-Plough delayed releasing ENHANCE for more than a year, even though the trial was actually completed in 2006.
The ENHANCE controversy spawned scores of lawsuits against Merck and Schering-Plough. Many accused the companies of marketing Vytorin and Zetia in a misleading fashion and failing to disclose the results of ENHANCE in a timely manner. Earlier this year, Merck and Schering-Plough agreed to pay $41.5 million to settle class-action lawsuits stemming from that debacle.